Screening and Functional Characterization of PIPK-FAB Associated Proteins in Rice under Multiple Environmental Stresses

To investigate the molecular mechanisms conducted by rice phosphatidylinositol phosphate kinase PIPK-FAB in regulating stress responses, yeast two-hybrid system was performed to identify its interacting proteins（OsPAPs）, along with transcriptomic analysis to assess their responses to environmental stresses. The results showed that PIPK-FAB was non-toxic to yeast strain AH109 and did not exhibit self-activation activity. 34 of positive clones were screened out from a rice cDNA library, and 20 interacting proteins were identified, including phosphoinositide-specific phospholipases, SNARE proteins, GTPase-activating proteins, ascorbate peroxidases, calmodulin-like proteins, and lectins. The RNA-seq data revealed that OsPAPs genes respond to various abiotic and biotic stresses such as salinity, drought, temperature extremes, and rice blast infection, exhibiting distinct expression patterns. These findings suggest that PIPK-FAB might serve as a key regulator in rice stress adaptation, and coordinates responses through multiple signaling pathways.